Summary of Work: Recurrent pulmonary symptoms and pneumonia in immunocompromised (IC) patients are common problems, and they pose diagnostic and therapeutic challenges. Repeat FOB is often performed because it is relatively safe, and more invasive procedures may be contraindicated. The purpose of this study was to evaluate the diagnostic and therapeutic efficacies of repeat FOB in IC patients. A retrospective chart review has been performed for all IC patients undergoing repeat FOB in our department from 1/1/87 through 6/30/92. Patients were classified as having either "persistent" pulmonary disease (as documented by repeat FOB performed within 30 days of initial FOB), or "new" disease (as documented by repeat FOB performed after 30 days from the initial FOB). In patients with HIV infection, a new diagnosis was found in 8 of 25 (32%) repeat FOB with new disease and, 2 of 20 (10%) with persistent disease (p = NS). In patients with other immunocompromised conditions, a new diagnosis was found in 3 of 10 (30%) repeat FOB with new disease, and 1 of 4 (25%) with persistent disease (p = NS); a change in therapy was initiated in 5 of 10 (50%) of cases with repeat FOB with new disease, and in 2 of 4 (50%) with persistent disease. We concluded that the diagnostic yield for repeat FOB in patients with HIV infection was equally effective in the presence of new or persistent disease; in patients with hematologic/oncologic disorders and new disease, repeat FOB may be more likely to establish a new diagnosis (fp=0.10). Data have been reviewed, and a manuscript is in preparation.